Malicious PDF — malware analysis report

Static analysis result for SHA-256 d66fa338edbe1831…

MALICIOUS

PDF

79.5 KB Created: 2021-09-18 09:48:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 49d46628545814dfc425e84471c0e3dc SHA-1: 0a9440a6417c9914471699cc0fe71fc1557e93f6 SHA-256: d66fa338edbe18319922fa186258d617ca7254e2d95609fe8873371e5fbd5c07
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF containing embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The high number of external links, many pointing to compromised CMS uploads and disposable hosting, strongly indicates a phishing or malware distribution campaign. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://nomylo.ru/uplcv?utm_term=get+into+onlyfans+free
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/cr9mpveqjcochd69cmo53idbon/68771265280.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137e9b4664e9---58914538688.pdf
    • https://photopoligrafic.ru/ckfinder/userfiles/files/sogizujuk.pdf
    • http://hk888.edo2008.com/com/comimg/file/20210911_153759_127.pdf
    • http://a-pluset.com/userfiles/48989172409.pdf
    • http://www.thaiboat.net/image/upload/File/bimenimebizagakigereniwet.pdf
    • https://marblobathware.com/app/webroot/img/files/27096643275.pdf
    • https://www.channeloflove.com/ckfinder/userfiles/files/mafotegoluwurudap.pdf
    • https://073741256.com/uploads/files/202109021910201832.pdf
    • http://dsagco.com/Upload/file/3712836636.pdf
    • http://teen.plovdivweek.com/js/ckfinder/userfiles/files/40951118792.pdf
    • http://kimsanghun.com/upload/userfiles/file/2021918148585970.pdf
    • http://micronforgacsolo.hu/UserFiles/file/10761902088.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614259c68e0a7---komugowi.pdf
    • http://toflight.mobi/attachment/ckeditor/files/69604a50b912198eec17676b626f3148.pdf
    • https://amgaa.org/temp/files/nukiburewo.pdf
    • https://kitapkaplama.com/upload/ckfinder/files/pexikeburomeka.pdf
    • https://aawyx.com/sites/default/imageuser/file/19006294482.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613eb2445f69a---30462336906.pdf
    • http://samuiluxurytravel.com/Uploads/file/35864976143.pdf
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/diwevemadikejevobi.pdf
    • https://cplastik.cz/data/cms/file/fagita.pdf
    • https://arhstroi.by/uploads/files/31235436152.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d626.bin
58203238e6a67bb7e490a18317a49a5ff60591da66b1c54f840e6f41fb53c9c3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD626 10360 bytes
font_01_sfnt_off0000edc0.bin
365163fdcf946617151c282f230ece20ecac2e81e358778622f55fef897d2e55
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDC0 16492 bytes
font_02_sfnt_off00011841.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11841 16792 bytes